When the Wischtech threatened to invade the fiefs of Szaalanden, the Emperor dispatched fourteen youths. Of these, the Seven Heroes halted the invasion to herald a time of prosperity while the four Lances of Betrayal were supposedly defeated.

Two decades later, the Lances of Betrayal have reappeared and formed a bandit militia near the frontier fief Gormbark. A man with a black sword and a scar over his left eye slays an entire troop of that militia. He is identified as the boy, Kóinzell, and becomes as much an object of fear as of hope even as his own past, motivations, and purpose are a mystery to those he meets on his journey.

From Volume 0's back cover (SBM's translation):
"When the black sword roars, everything that stands before it is crushed . . . ! What is the purpose of a boy Kaintzel who possesses transcendent sword skills? The battle with the "Lances of Betrayal" that were supposed defeated by the 7 Heroes... And the astounding truth that is revealed after the battle."

Volume 0 encompasses a plot arc which leads directly into the main plot of Übel Blatt in Volume 1. It also introduces and develops the attitudes and motives of a few other characters aside from Kóinzell.

From Suvi of IIDX, Heartfang and Hinokaze

20 years ago, 14 heroes set out on a journey to stop the Wischtech threat. Three perish along the way and four abandon their mission and are labeled hence forth as the Lances of Betrayal. The remaining seven heroes destroy the Wischtech, fulfill their sealing mission and rid the world of the Lances of Betrayal. They return and become the pillars of support for the rebuilding of the empire. So forth the prestigious era starts.

Although the Lances of Betrayal were thought to have fallen, they return and begin forming a powerful army on the frontier. They pillage the towns, ravage the lands, and become the object of fear within the empire. Only a young man named "Koinzell", holder of the "Black Blade", has the power to annihilate these "Lances of Betrayal". Who is Koinzell? What is the object of his journey? Where did he come from? Could he be connected to the "Seven Heroes"?

The series Ubel Blatt has been licensed, it is not available in Manga Fox.